Ozone depletion and global warming

Ozone depletion and global warming currently enjoy a much higher profile than the other environmental issues, both in the media and in the scientific community. They are the focus of major research efforts costing millions of dollars aimed at deciphering the causes and effects of the problems so that solutions can be identified. The intensity of the research effort has ensured some success, but in many cases the search for information has done little more than confirm the complexity of the earth/atmosphere system. Interest in the topics has been developed and maintained through a continuing series of high level international conferences, some of which concentrate on the technical aspects of the problems, while others involve policy development and decision-making. These are complemented by national and regional conferences dealing with specific aspects of the problems.

Progress in the development of the topics has not been even. Consideration of ozone depletion has already reached the decision-making stage, whereas in the study of global warming the technical aspects of the issue—such as the establishment of the nature, extent and timing of the warming—continue to receive much of the attention. This may reflect the relative complexity of the two issues. Controlling CFCs is relatively easy, for example, because their uses are limited, the small number of producers can be easily identified and production can be monitored. Substitutes for many CFCs have been developed quite easily. In contrast, greenhouse gas production is widespread, with a mixture of natural and anthropogenic sources which are difficult to monitor with any accuracy. The size and complexity of the problem is such that there has been little development of replacements for the products and processes releasing greenhouse gases. The greater progress in dealing with thinning ozone is also an indication of the different ways in which the problems are perceived. Of the two, ozone depletion is usually seen as having the most serious consequences. The discovery of the Antarctic ozone hole was followed closely by the initiation of international efforts to save the ozone layer, which gained momentum with every new report of ozone depletion.

The Vienna Convention on the Protection of the Ozone Layer, which emerged from a 1985 conference, was followed in 1987 by the Montreal Protocol. Signatories to the Protocol agreed to reduce production of CFCs by 50 per cent (of 1986 values) by 2000. The concluding statement of the World Conference on the Changing Atmosphere, held in Toronto, Canada in mid-1988, also included reference to CFCs. It called for them to be phased out by the year 2000, and, later that year, delegates at the World Conference on Climate and Development in Hamburg, Germany recommended a global ban on the production and use of CFCs by 1995. In March 1989, the members of the European Community agreed to eliminate production and use of ozone-destroying chemicals by the end of the century. The US government endorsed the effort, but stressed the importance of finding safe substitutes for CFCs. In Australia in 1989, the government passed the Ozone Protection Act which, with supplementary regulations, was aimed at eliminating CFC and halon use by 1994. At about the same time, major, government-sponsored conferences in London and Paris provided international support for a worldwide ban on CFCs and other environmentally harmful chemicals. Subsequent meetings have confirmed the willingness of the nations of the world to deal with the issue, and the second half of the 1990s will see the progressive elimination of CFCs and other ozone-destroying compounds. There is already evidence of a decrease in the growth rate of atmospheric halons (Butler et al. 1992) and certain CFCs (Elkins et al. 1993). The growth of CFC-11 and CFC-12 is slowing, for example, and if this continues as expected, the volume of these gases in the atmosphere will reach a peak by the end of the century, and then begin to decline. Even with such developments, the ozone layer will take time to recover, and levels of UV-B rays reaching the earth's surface will remain high. In October 1993, for example, the US National Oceanic and Atmospheric Administration announced that the amount of ozone in the atmosphere above Antarctica had reached a record low, being virtually absent between 13.5 km and 18 km above the surface. Announcements such as this apparently confirming the progressive thinning of the ozone, have prompted government agencies from as far apart as Australia and Canada to issue warnings about exposure to excess ultraviolet radiation, and these warnings are currently among the most obvious manifestations of the ozone problem.

Like ozone depletion, global warming has been the subject of a large number of conferences and workshops—from Villach in 1985, where the original investigative framework was set up, to Rio in 1992, where it was considered as a major element in the broader study of global change. The net effect has been the accumulation of a considerable body of knowledge on all aspects of global warming, and a recently published annotated bibliography lists several hundred publications on the topic (Handel and Risbey

1992). Much of the material is complex, written in the scientific jargon of research reports, but, perhaps more than any of the other issues, the greenhouse effect has been treated by the media in such a way as to stimulate public interest in the problem. Government organizations have also published the evidence from the research reports in a simplified form for media use and public consumption. The Climate Change Digests of the Canadian Atmospheric Environment Service are a good example of this approach. In addition, private, non-profit organizations—such as the Climate Institute in the United States— have been formed to advance public understanding of the global warming produced by the enhanced greenhouse effect.

The success of these endeavours is difficult to measure, as yet, but the public approach is becoming more common. It reflects the general consensus in the scientific community that solutions to current large-scale environmental problems can only be implemented successfully if they have a high level of public support, and that such support is most likely to come from a public kept well-informed about the nature and extent of the problems. As the investigation of global warming enters the decision-making phase, and solutions involving such elements as tax increases and lifestyle changes are proposed, maintaining that public support will become increasingly important.

The Basic Survival Guide

The Basic Survival Guide

Disasters: Why No ones Really 100 Safe. This is common knowledgethat disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

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